Method of making textile fiber drafting elements containing animal glue, a rubber, and a surface-active material



METHGD OF MAKING TEXTILE FIBER DRAFT- ING ELEMENTS CQNTAINING ANIMAL GLUE, AEFBBER, AND A SURFACEACTHVE MATE- RI Richard A. Garrett, Manor Township, Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania No Drawing. Application May 3, 1954 Serial No. 427,344

5 Claims. (Cl. 260-8) This invention relates to a method of making textile fiber drafting elements containing a matrix of rubber, such as a rubbery butadiene-acrylonitrile copolymer, glue, and a surface-active material. The invention will be considered specifically with respect to the preparation of compositions for the manufacture of textile drafting cots from a matrix of butadiene-acrylonitrile type synthetic rubber as typical of the field to which the invention is directed.

The present invention is related to my copending application No. 427,343, filed concurrently with this application and entitled Textile Fiber Drafting Element Containing a Surface-Active Material, now Patent No. 2,811,752. In that application there is disclosed and claimed a textile fiber drafting element having a working surface made of a mixture of a vulcanized rubber-like butadiene-acrylonitrile copolymer, animal glue, and a compatible surface-active material.

Where relatively large proportions of surface-active material are to be combined with butadiene-acrylonitrile synthetic rubber and animal glue, the surface-active material does not serve as a dispersing agent as might be expected. Rather, it causes the glue to be deposited as discrete or agglomerated particles through the mix. The exact action which occurs is not fully understood, but it is possible that the surface-active material, in some instances at least, insolubilizes the surface of the individual glue particles, preventing them from breaking down under mixing conditions and becoming uniformly dispersed in the rubber matrix. Where the glue is swollen in water prior to its addition to the rubber batch, the glue particles are in some manner affected adversely by the surface-active material, preventing their uniform distribution throughout the mass when more than a relatively small amount of such material is employed. The problem is particularly acute where the quantity of surface-active material represents 4% or more of the total weight of the animal glue. Minor amounts of surface-active material may be combined, following conventional rubber-making techniques; but, as disclosed in my Patent 2,811,752 referred to, for textile fiber drafting purposes it is often desired to incorporate 30 or more parts of surface-active material for each 100 parts of glue. The method of the present invention is applicable to the fabrication of the textile fiber drafting elements of my Patent 2,811,752 when using a relatively large proportion of surface-active material, many examples of which surface-active materials are set forth in said patent.

An object of the present invention is to provide a method whereby a relatively large volume of surfaceactive material may be compounded in a rubber mixture including animal glue, with the various compounding ingredients being substantially uniformly distributed throughout the synthetic rubber base or matrix, essen- States Patent tially free of agglomerates of particles of animal glue, i. e., visually discernible lumps of the glue.

According to the present invention, the animal glue is combined with the rubber, the glue preferably being in the form of a water-swollen mass. Mixing may be accomplished in a Banbury mixer, for example, followed by more intensive mixing and drying on a conventional two-roll mill. Milling is preferably continued until essentially complete and uniform dispersion of the glue in the rubber has been accomplished. Thereafter the surface-active material and the other compounding ingredients are added to the dried rubber-animal glue master batch, It has been found that if this procedure is followed, from 4 to parts or more of surfaceactive material for each 100 parts of glue may be incorporated successfully into the batch and a thorough and uniform dispersion of all of the ingredients obtained. There is no tendency whatsoever for the surface-active material to affect the animal glue deleteriously.

The following examples illustrate the practice of the invention.

Example I Parts by weight Butadiene-acrylonitrile rubber e. g. Chemigum N4 100.0 Animal glue 50.0 Curing agent, e. g. sulfur 10.0 Curing accelerator .5 Activator, e. g. zinc oxide 5.0 Plasticizer 8.7 Pigments and fillers 15.3

Nonionic surfactant e. g. polyethylene glycol (400) monolaurate 15.0

The foregoing example is Example I of my copending application referred to above. In the preparation of the composition the 50 parts of animal glue may be mixed with 10 parts of water and permitted to swell for a period of 24 hours. Thereupon, the synthetic rubber may be charged to a Banbury mixer and the swollen glue mixture added thereto. Mixing may be effected for a period of 20-60 minutes in the Banbury with the stock attaining a temperature in the order of 200 F. This mixing will effect distribution of the swollen glue mass throughout the synthetic rubber, but to obtain a better distribution which is desirable in the preparation of textile fiber drafting elements, the mass may be discharged from the Banbury mixer onto a tworoll mill and milling accomplished until the product has been substantially completely dried. This will require in the order of 10 to 25 minutes, depending upon the Banbury mixing time, mill temperature, and other variable factors. The mill temperature may be maintained at about 200 F. The mass will of course attain a higher temperature, due to the internal frictional heat developed in the mass in this intensive mixing operation. When the mass has been fully and completely dried and the animal glue uniformly distributed throughout the mass, the nonionic surfactant may be added The following example illustrates the invention employing a cationic surfactant:

Exizmple II Parts by weight Butadiene-acrylonitrile rubber e. g. Paracril 26 In the preparation of this composition, the synthetic rubber and animal glue, the glue being in the form of a water-swollen mass, are fully interspersed by blending, mixing, and drying, and then the cationic surfactant which constitutes about 8% of the weight of the glue (4 parts of amide of polyamine stearate with '50 parts of animal glue) may be added to the batch on the mill, together with the other compounding ingredients after complete interspersion of the glue in the rubber. The procedure followed may be the same with either the nonionic or the cationic surfactants or mixtures of them.

The method of this invention is not concerned with any specific surfactants or any specific synthetic rubber but is directed to a method in which the animal glue and the surfactant are compatible with the selected rubber to produce a composition which may be suitable for uses Where sweating out of incompatible ingredients would be objectionable. Where oil resistance is a desired feature in the finished product, butadiene-acrylonitrile synthetic rubber, neoprene, or the like may be used. Where oil resistance is not important, butadiene-styrene rubber or natural rubber may be used. The terms rubber and rubber matrix are used to comprehend all of the various natural and synthetic'rubbers which may be compounded with animal glue and relatively large volumes of surfactants in accordance with this invention.

The proportioning of the various ingredients is not critical, except in the sense that the problem of incorporating quantities in excess of 4 parts of surface-active material on the basis of each 100 parts of animal glue is acute, and the method of the invention solves that problem.

I claim:

1. In a method of making a textile fiber drafting element containing a rubber, animal glue, and at least 4 parts of a surface-active mterial for each 100 parts of glue, the steps comprising mixing animal glue with a rubber until said glue is essentially uniformly distributed throughout the rubber matrix, thereafter mixing into the animal gluerubber master batch so prepared at least 4 parts of material selected from the group consisting of nonionic and cationic surface-active materials .and mixtures thereof for each 100 parts of glue to form a substantially uniformly distributed mixture of rubber, glue, and surface-active material essentially free of agglomerates of animal glue, adding to said rubber matrix at any stage of processing a vulcanization agent, forming the rubber stock to the desired shape for a textile fiber drafting element, and vulcanizing the same.

2. In a method of making a textile fiber drafting element containing butadiene-acrylonitrile rubber, animal glue, and at least 4 parts of a surface-active material for each 100 parts of glue, the steps comprising mixing animal glue with a rubbery copolymer of butadiene and acrylonitrile until the glue is essentially uniformly distributed throughout the rubber matrix, thereafter mixing into the animal glue-rubber master batch so prepared at least 4 parts of material selected from the group consisting of nonionic and cationic surface-active materials and mixtures thereof for each parts of glue to form a substantially uniformly distributed mixture of rubber, glue, and surface-active material essentially free of agglomerates of animal glue, adding to said rubber matrix at any stage of processing a vulcanization agent, forming the rubber stock to the desired shape for a textile fiber drafting element, and vulcanizing the same.

3. In a method of making a textile fiber drafting element containing a rubber selected from the group consisting of natural rubber, butadiene-acrylonitrile synthetic rubber, neoprene synthetic rubber, and butadiene-styrene synthetic rubber, animal glue, and at least 4 parts of a surfaceactive material for each 100 parts of glue, the steps comprising forming a mixture of animal glue and Water into a swollen animal glue-water mixture, mixing said animal glue-water mixture with said rubber under conditions which will cause said glue to be essentially uniformly distributed throughout the rubber matrix, thereafter mixing into the animal glue-rubber master'batch so prepared at least 4 parts of material selected from the group consisting of nonionic and cationic surface-active materials and mixtures thereof for each 100 parts of glue to form a substantially uniformly distributed mixture of rubber, glue, and surface-active material essentially free of agglomerates of animal glue, adding to said rubber matrix at any stage of processing a vulcanization agent, forming the rubber stock to the desired shape for a textile fiber drafting element, and vulcanizing the same.

4. In a method of making a textile fiber drafting element containing butadiene-acrylonitrile rubber, animal glue, and at least 4 parts of a surface-active material for each 100 parts of glue, the steps comprising forming a mixture of animal glue and water into a swollen animal glue-water mixture, mixing said animal glue-Water mixture with a rubbery copolymer of butadiene-acrylonitrile under conditions which will cause said glue to be essentially uniformly distributed throughout the rubber matrix and said water to be essentially all removed from said mixture, and thereafter mixing into the animal glue-rubber master batch so prepared at least 4 parts of material selected from the group consisting of nonionic and cationic surface-active materials and mixtures thereof for each 100 parts of glue to form a substantially uniformly distributed mixture of rubber, glue, and surface-active material essentially free of agglomerates of animal glue, adding to said rubber matrix at any stage of processing a vulcanization agent, forming the rubber stock to the desired shape for a textile fiber drafting element, and vulcanizing the same.

5. In a method of making a textile fiber drafting element containing butadiene-acrylonitrile rubber, animal glue, and at least 4 parts of a surface-active material for each 100 parts of glue, the steps comprising mixing animal glue with a rubbery copolymer of butadiene and acrylonitrile until the glue is essentially uniformly distributed throughout the rubber matrix, thereafter mixing into the animal glue-rubber master batch so prepared at least 4 parts of nonionic surface-active material for each 100 parts of glue to form a substantially uniformly distributed mixture of rubber, glue, and surface-active material essentially free of agglomerates to animal glue, adding to said rubber matrix at any stage of processing a vulcanization agent, forming the rubber stock to the desired shape for a textile fiber drafting element, and vulcanizing the same.

References Cited in the file of this patent UNITED STATES PATENTS 2,450,409 Baymiller Oct. 5, 1948 2,498,638 Baymiller Feb. 28, 1950 2,579,375 Eisen Dec. 18, 1951 2,624,725 Bjorksten et a1. Jan. 6, 1953 2,636,878 Garrett Apr. 28, 1953 2,729,860 Balkin et a1. Jan. 10, 1956 

1. IN A METHOD OF MAKING A TEXTILE FIBER DRAFTING ELEMENT CONTAINING A RUBBER, ANIMAL GLUE, AND AT LEAST 4 PARTS OF A SURFACE-ACTIVE MATERIAL FOR EACH 100 PARTS OF GLUE, THE STEPS COMPRISING MIXING ANIMAL GLUE WITH A RUBBER UNTIL SAID GLUE IS ESSENTIALLY UNIFORMLY DISTRIBUTED THROUGHOUT THE RUBBER MATRIX, THEREAFTER MIXING INTO THE ANIMAL GLUERUBBER MASTER BATH SO PREPARED AT LEAST 4 PARTS OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF NONIONIC AND CATIONIC SURFACE-ACTIVE MATERIALS AND MIXTURES THEREOF FOR EACH 100 PARTS TO GLUE TO FORM A SUBSTANTIALLY UNIFORMLY DISTRIBUTED MIXTURE OF RUBBER, GLUE, AND SURFACE-ACTIVE MATERIAL ESSENTIALLY FREE OF AGGOLMERATES OF ANIMAL GLUE, ADDING TO SAID RUBBER MATRIX AT ANY STAGE OF PROCESSING A VULCANIZATION AENT, FORMING THE RUBBER STOCK TO THE DESIRED SHAPE FOR A TEXTILE FIBER DRAFTING ELEMENT, AND VULCANIZING THE SAME. 